Notices
1987 - 1996 F150 & Larger F-Series Trucks 1987 - 1996 Ford F-150, F-250, F-350 and larger pickups - including the 1997 heavy-duty F250/F350+ trucks

1990 f150 problem

Thread Tools
 
Search this Thread
 
Old Dec 9, 2012 | 04:35 PM
  #1  
parkerparkerm's Avatar
parkerparkerm
Thread Starter
|
Elder User
Joined: Jun 2012
Posts: 650
Likes: 0
From: Plant city florida
1990 f150 problem

Well I traded my 76 for this truck, mistake #1. Day after I bought it the FPR went out, replaced it with the plenum on. Still ran bad but it was high idle now, replaced the missing plenum gasket, not it bounces off the rev limiter at idle. I've replaced the throttle body gasket and the idle air solenoid, I know for a fact everything is hooked up and the timing has never changed. What the hell is wrong with it, I dont know. What do you guys think it is? What's this things scrap value or part-out value? It's a RC SB with an Inline6 and an m5OD. I'm tired of working on this POS for it to run worse. I have very little money as I'm a high schooler and I'm fixing a 77 highboy that was wrecked. I never planned to keep this truck but it looks like I'm going to keep it for a lot shorter than I expected.

On a side note, anybody want a parts truck that's located in plant city Florida? Will not deliver and make offer.
 
Reply
Old Dec 10, 2012 | 07:20 AM
  #2  
bdelmar2's Avatar
bdelmar2
Senior User
Joined: May 2010
Posts: 285
Likes: 0
I would say its a fair chance you have a vacuum leak somewhere.

Since you replaced the fpr you were working in the area where the pcv hose connects to the intake manifold. I would say you knocked it off as a guess.

On the '88 truck I have and the '89 parts engine the pcv hose connects to the underside of the upper manifold roughly in the center.


If I were you however I would fix it, these trucks run forever with minimal maintainence once you get them straighted out.
 
Reply
Old Dec 10, 2012 | 08:46 AM
  #3  
SCRebel's Avatar
SCRebel
Fleet Mechanic
10 Year Member
Joined: Jun 2011
Posts: 1,324
Likes: 3
From: Conway, South Carolina
Worst comes to worse you always have the option of a EFI to carb swap.
 
Reply
Old Dec 10, 2012 | 10:28 AM
  #4  
burnout400m's Avatar
burnout400m
Posting Guru
Joined: Oct 2011
Posts: 1,179
Likes: 1
From: Pueblo, CO
I would recommend Checking for vacuum leaks and pulling the codes even if the CEL isn't on. The ECM might be bad.
 
Reply
Old Dec 10, 2012 | 11:04 AM
  #5  
dixie460's Avatar
dixie460
Postmaster
Joined: Nov 2011
Posts: 3,533
Likes: 17
From: SW Florida
Don't give up, I would do as suggested and check for vacuum leaks. Check ALL of the lines, not just one's you've worked on. Also if you have any unused vac ports that are capped off, check the caps on them. I found a few on my truck where the cap crumbled in my hand when trying to remove them.

The parts store has vac caps for maybe $3 for a box of assorted sizes.
 
Reply
Old Dec 10, 2012 | 11:33 AM
  #6  
DPDISXR4Ti's Avatar
DPDISXR4Ti
Fleet Mechanic
10 Year Member
Photogenic
Liked
Loved
Joined: Nov 2011
Posts: 1,823
Likes: 43
From: New York
Originally Posted by SCRebel
Worst comes to worse you always have the option of a EFI to carb swap.
While that is an option, there's barely any sensible reason to suggest that as a good option.

Given that you're in FL (i.e. heat-land), I would definitely pull the PCM and open up the case to see if you have any leaking capacitors. This is an ever increasing problem as the components age, and heat only further accelerates the break-down.
 
Reply
Old Dec 10, 2012 | 03:47 PM
  #7  
parkerparkerm's Avatar
parkerparkerm
Thread Starter
|
Elder User
Joined: Jun 2012
Posts: 650
Likes: 0
From: Plant city florida
Me and my grandpa played with it for an hour, adjusted timing, unplugged ALOT of stuff and plugged it up again, and its running better but he says there's a leak in the plenum. Ill have my dad check it out when I'm at school tomorrow. If I don't get it fixed I'm trading it for a set of 37" militaries, I'm just so fed up with it.
 
Reply
Old Dec 10, 2012 | 10:22 PM
  #8  
SCRebel's Avatar
SCRebel
Fleet Mechanic
10 Year Member
Joined: Jun 2011
Posts: 1,324
Likes: 3
From: Conway, South Carolina
You can spray carb cleaner or water around the intake and if the truck gains rpm's or stalls you got a intake leak.
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

Top 10 Fords at 2026 Carlisle Ford Nationals

 Joe Kucinski
story-1

3 Best / 3 Worst Parts of Modern Ford Ownership

 Brett Foote
story-2

10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

 Pouria Savadkouei
story-3

Every 2026 Ford Engine Explained

 Brett Foote
story-4

10 Ugly Ford Trucks That We Still Kinda Love

 Joe Kucinski
story-5

10 Things Every Truck Owner NEEDS (2026 Edition)

 Michael S. Palmer
story-6

Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

 Verdad Gallardo
story-7

Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

 Joe Kucinski
story-8

2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

 Brett Foote
story-9

Top 10 Ford Truck Tragedies

 Joe Kucinski
Old Dec 14, 2012 | 06:35 PM
  #9  
parkerparkerm's Avatar
parkerparkerm
Thread Starter
|
Elder User
Joined: Jun 2012
Posts: 650
Likes: 0
From: Plant city florida
Is it possible the 02 or whatever other exhaust sensors is bad?
 
Reply
Old Dec 14, 2012 | 07:43 PM
  #10  
DPDISXR4Ti's Avatar
DPDISXR4Ti
Fleet Mechanic
10 Year Member
Photogenic
Liked
Loved
Joined: Nov 2011
Posts: 1,823
Likes: 43
From: New York
Originally Posted by parkerparkerm
Is it possible the 02 or whatever other exhaust sensors is bad?
Possible, but highly unlikely that's your problem. Have you checked the PCM like I suggested? Have you pulled error codes? Have you fixed your reported vacuum leak?
 
Reply
Old Dec 14, 2012 | 07:53 PM
  #11  
parkerparkerm's Avatar
parkerparkerm
Thread Starter
|
Elder User
Joined: Jun 2012
Posts: 650
Likes: 0
From: Plant city florida
I fixed the leak we found, bolts were just barely too loose. Where is the PCM?
 
Reply
Old Dec 14, 2012 | 09:51 PM
  #12  
DPDISXR4Ti's Avatar
DPDISXR4Ti
Fleet Mechanic
10 Year Member
Photogenic
Liked
Loved
Joined: Nov 2011
Posts: 1,823
Likes: 43
From: New York
Originally Posted by parkerparkerm
Where is the PCM?
It's located behind the driver-side kick panel. You'll unbolt the harness quick-connector from the engine bay with a 10mm socket.
 
Reply
Old Dec 15, 2012 | 05:46 AM
  #13  
parkerparkerm's Avatar
parkerparkerm
Thread Starter
|
Elder User
Joined: Jun 2012
Posts: 650
Likes: 0
From: Plant city florida
Ok we'll look for it next time I've got time
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
evan_nugget
Ford Inline Six, 200, 250, 4.9L / 300
10
Mar 22, 2018 07:11 PM
theonefordfan
FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428)
6
Mar 8, 2015 09:47 AM
enrgizerbunny
Ford Inline Six, 200, 250, 4.9L / 300
9
Dec 6, 2013 04:42 AM
kevinvb
Computer Chips & Tuners
3
Nov 24, 2008 10:47 AM
island
1987 - 1996 F150 & Larger F-Series Trucks
3
Aug 3, 1999 01:29 PM




All times are GMT -5. The time now is 02:08 AM.

story-0
Top 10 Fords at 2026 Carlisle Ford Nationals

Slideshow: Top 10 Fords at 2026 Ford Nationals

By Joe Kucinski | 2026-06-09 11:10:08


VIEW MORE
story-1
3 Best / 3 Worst Parts of Modern Ford Ownership

Based on years of owning multiple modern Ford products.

By Brett Foote | 2026-06-09 10:53:36


VIEW MORE
story-2
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

SPONSORED: From muddy boots to rain-soaked cargo, these upgrades address some of the most common frustrations Ford truck owners face every day.

By Pouria Savadkouei | 2026-06-08 18:50:34


VIEW MORE
story-3
Every 2026 Ford Engine Explained

Here's everything you need to know about every Ford engine available for the 2026 model year.

By Brett Foote | 2026-06-05 12:58:01


VIEW MORE
story-4
10 Ugly Ford Trucks That We Still Kinda Love

Slideshow: 10 ugly Ford trucks that we still kinda love.

By Joe Kucinski | 2026-06-03 09:51:16


VIEW MORE
story-5
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-03 15:43:58


VIEW MORE
story-6
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-06-03 11:38:36


VIEW MORE
story-7
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Slideshow: 10 most expensive Ford trucks ever sold on Bring a Trailer.

By Joe Kucinski | 2026-05-27 16:24:34


VIEW MORE
story-8
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Here's everything that has changed for the latest model year.

By Brett Foote | 2026-05-27 16:17:28


VIEW MORE
story-9
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE